I have a 2009 Harley Iron. I put a current clamp around this cable going to the solenoid (See Pic)....It's registered 538Amps peak....



I was trying to catch the starter cranking amps and this was the only wire i could see near enough to the starter....
THe battery is 200CCA so how could I have registered 538Amps

Thanks for any insights

 

That's entirely possible. You are seeing the peak inrush current to the starter motor. It only lasts for milliseconds or less at that level.

Not sure what current clamp you are using, but try looking at RMS Amps instead of peak current (Amps).

 

Is your current clamp rated for DC voltage?

 

Hiya,
yup the current clamp is rated for DC current...IT's a 'Brymen BM189'

supposedly did well in the 2013 multimeter ratings

I'll take a mesurement again after reading the instructions,, It says 'True RMS' whatever that is so I should be able to do that reading too!

THanks

 

True RMS reading is actually AC. If you have Amps DC range use that, if not try RMS. It looks like you used Peak current for the original reading.

Just looked at that clamp. Make sure crest is off. If it's on you're measuring inrush current

 

that 5 year old dirt is giving it a false reading lol

 

Nearly every motor made that is DC or AC has approximately 2 1/2 times the amps on startup (for an instant only) as the running amps after the motor is at running speed. This is completely normal. The battery rating won`t reflect this, as for normal operation will not be detrimental to the battery or wiring. In fact, this may be even more for a DC motor. Nothing to worry about.

 

Thanks Guys,
I retested it by just leaving the DC current measurement on and trying to get a quick view at it while I cranked the engine....I saw 180Amp...

I made the mistake as pointed out earlier of leaving the 'crest' function on.

THe brother rekcons he saw 260Amp, but maybe the meter just caught it near that peak rush....
ANyway, seems to be within spec